And within 24 hours, it was, as James and his colleagues fended off hostility from the Daily Mail and the Daily Telegraph and found themselves talking to the anti-terrorist squad.

Before long, they were facing a clamour – generated via the web – for the Islamic Society to be closed, or at least reconfigured so as to shield its members from anyone who might conceivably be construed as a radicaliser. Didn't it play host last year to radical speaker Abu Usamah, who was secretly filmed by Channel Four praising Osama bin Laden? Haven't other questionable types been given platforms there?

The answer from the union emerged this week. Nothing doing. "Of course it is going to be difficult and I am sure we will get some stick, but we are going to defend the Islamic Society and its right to hear from controversial speakers," James tells me over coffee. "We will not allow extremist activities. But at the same time we are determined not to yield. The Islamic Society is not a hotbed of extremists. Its activities are prayer meetings, cultural events, debates and music. We are going to stand up for freedom and tolerance. Surely that's what the terrorists want to destroy."

The UCL campus contains more than 140 nationalities and countless religions. They learn history and geography; some, like the would-be bomber, learn engineering. But that is the least of it. They also learn that the world is messy and contentious and requires fine judgments. And that even the cleverest people sometimes spout rubbish, go bad and do things that have scant basis in logic. If that's all they learn, that's fine.